1. Field
Aspects of the invention relate generally to pneumatic actuators or switches. More particularly, bellows-action, remote pneumatic actuators are disclosed, wherein such actuators are preferably sterile or sterilizable, and configured for one-time use.
2. Description of the Related Art
There are many examples of electric powered devices that require a remotely controlled on-off switch. For example, with a ceiling light bulb, a remote on-off switch facilitates efficient utilization. A more specific example is an electric powered medical device such as a peristaltic infiltration pump used by a surgeon.
When using such a pump, a surgeon wears sterile gloves and holds a sterile infiltration cannula connected to plastic pump-tubing, similar to intravenous tubing, which in turn is connected to a reservoir of sterile solution. The clinical goal is to inject a controlled volume of solution through the infiltration cannula and into a patient's subdermal or deep tissues.
In this setting, the reservoir of sterile solution and the peristaltic pump, the outer surfaces of which are not sterile, are positioned remotely from the aseptically prepared and sterilely draped surgical site. The sterile solution is transported via a peristaltic roller pump tubing set that connects the reservoir to the infiltration cannula. The patient end of this tubing set, as well as the infiltration cannula held by the surgeon, come into contact with the surgical site and must remain sterile. The other end of the tubing which is connected to the reservoir and passes through the peristaltic pump is not intended to have a sterile external surface.
In order to actuate and operate the pump with finesse during surgery, the surgeon must have easy access to a remotely controlled on-off switch. During surgery the surgeon wears gloves which must remain sterile throughout the duration of the procedure. Thus any surgeon-controlled on-off switch is typically either a sterile hand-held switch or a non-sterile foot-pedal switch.
When a surgical procedure requires two or more remotely controlled electrically powered devices, the surgeon must be in control of two or more on-off switches. For example, the surgery might require the use of multiple electrically powered devices such as, for example, a peristaltic infusion pump, an electric suction-vacuum pump, a laser device or an electric cautery device. In order to avoid the risks of an electric shock to the patient or the surgeon, it is desirable that the on-off switches that control electrically powered surgical devices be connected to the surgical devices by materials that do not conduct an electric current.
One option is a disposable battery-operated hand-control which utilizes radio frequency or infra-red frequency electromagnetic waves. However, disposable battery-operated hand-controls are relatively expensive and require battery disposal protocols. A battery powered remote-controlled disposable pump connected by copper wires to a handheld switch also has the disadvantage of being relatively expensive. See e.g., the StrykeFlow2 (San Jose, Calif. 95138), a battery operated suction and irrigation system with a disposable hand piece and built-in pump motor; See also U.S. Pat. Nos. 5,484,402; 6,213,970; 6,623,445; and 6,652,488; incorporated herein in their entireties by reference thereto.
Another option is the use of a foot pedal switch. The advantage of a foot pedal switch is that it need not be sterile and can be reused many times. However, there are several disadvantages of a foot switch. Firstly, foot-eye coordination is not as precise as hand-eye coordination. Second, the surgeon must occasionally remove his/her attention and visual focus from the patient and the surgical field in order to visually locate the foot pedal. Third, when there are two or more foot pedals, the surgeon's attention and vision must frequently be diverted toward the floor in order to be certain that the surgeon's foot is being placed on the correct foot pedal switch. Fourth, foot pedals, wires, cords, and tubes which are located on a surgical operating room floor are easily contaminated by blood-born pathogens and therefore must be washed or cleaned after each surgery, which is an expensive and labor intensive process. Fifth, in situations where there are multiple pedals and tubes or wires on the operating room floor, there is a serious risk of tripping on the tangled cords with subsequent injury to staff or the patient.
In order to avoid confusion and possible mistakes, the multiple foot switches must each have a distinct and easily recognized appearance. Such a solution is problematic in any clinical situation which requires a darkened or low-light operating room environment. Furthermore, the risk of inadvertently stepping on the wrong foot switch or tripping on a tangle of tubing on the floor cannot be entirely eliminated. The use of a foot-switch necessarily entails some constraint on a surgeon's ability to choose an optimal body posture and foot position. A challenging or difficult surgical maneuver often requires that the surgeon be able to maintain a comfortable and stable body position with weight appropriately distributed on each foot.
Another option for an on-off switching apparatus that does not conduct an electric current is a combination of a pneumatic bellows-action hand-control connected by means of plastic tubing to a pneumatic diaphragm-triggered electric switch located within the remote electrically powered surgical device. Such a switching means can be either reusable or disposable.
Reusable, pneumatic, bellows-action hand-controls are not generally designed for use in a sterile setting. A reusable, hand-control on-off switch for a surgical device must be sterilizable, e.g., by heat sterilization in a steam autoclave. Such design requirements result in a device that is expensive to manufacture. Furthermore, reusable bellows-action hand-control switches may be prone to increased risk of transmitting blood borne pathogens.
Existing bellows-action hand-controls are intended for reusable use in non-medical industries. Modifying such reusable hand-control switches for a specific clinical situation is often prohibitively expensive, and the switch may be awkward to use. At present the only commercially available pneumatic bellows-action hand-control devises are rather cumbersome, not easily sterilized and expensive.
Remote control on-off switches are known in the art. Such switches are designed to provide convenient activation of a remote electrical device. However, despite the development of many approaches to such switches, these approaches often have significant drawbacks.
Accordingly, there is a need for a pneumatic, e.g., bellows-action, hand-held remote actuator, that is safe (e.g., does not conduct an electrical current), inexpensive, light-weight, small, reliable and with few moving parts, that can be easily coupled to one or more surgical devices. Preferably, the remote actuator is sterile or sterilizable and disposable.